The manufacture of electrical motors has experienced a continuing evolution in the effort to reduce cost. The stator of small induction motors, and particularly the case of small synchronous or stepping type motors which may involve six or more poles, coils have been separately wound and then inserted on the poles formed by the stator stack or core. The separate winding of the coils permitted sets of coils to be wound from a continuous wire so that after the coils were positioned on the stack, interconnection of the coils was already complete and only the external leads to the coils had to be attached. In the past, the stranded lead wires were soldered directly to the ends of the coil wires and the soldered joints were insulated and secured in place by sewing into the coil head. This method of wiring the stators required a considerable amount of hand labor.
Various techniques have heretofore been proposed for machine wiring the coils directly on the stack. While such techniques have been developed for larger size motors, only recently have machine wiring techniques been developed which are capable of winding coils on very small size stator stacks. However, machine wiring has presented a problem in interconnecting the coils and the external leads. Unlike hand-wired coils, the machine-wired coils cannot effectively be wound in sets from a continuous wire. This means that internal connections have to be made between pairs of coils on opposing poles after the winding process is completed. Furthermore the much tighter winding of the coils of wire have made it difficult to effectively tie leads to the coils. This has made it difficult to secure the leads and the intercoil connections in the stator structure.
One method utilized in the past has been to provide a terminal board secure to the frame of the motor to which the coil ends are brought out and secured after the stator is mounted in the motor frame. External leads are then secured to the terminal board to complete the stator wiring connections. Because the board is spaced from the coil, unsupported lengths of solid copper coil wire results from this type of construction and because the coil wire is fragile and subject to fatigue, and fracturing under continuous vibration, external connections of this type have not proved entirely satisfactory. Thus the savings in machine winding of the coils has been minimized by the difficulties experienced in forming the interconnection between the coils and with the external leads.